Roof ridge ventilators are installed overlying the open roof ridge and along the length of a building for exhausting heated air from the space below the roof of the building, such as he attic of a house or small commercial/industrial building or the like. These ventilators typically are installed in cooperation with ventilators positioned in the soffits of the building roof to provide a ventilation system in which air is exhausted from the attic through the roof ridge ventilator and is replenished through the soffit ventilators.
In an optimum roof ridge soffit ventilator system, there is a balance between the net free open area presented by both the roof ridge and soffit ventilators. The phrase "net free open area of a ventilator" is intended to mean the cross-sectional area of a ventilator which is open for passage of air therethrough. A balance between the net free open area of a roof ridge and soffit ventilator is difficult to obtain. In many new homes there is a lack of sufficient soffit area in which to provide the soffit ventilators while many existing homes do not have sufficient existing soffit ventilation to provide the balanced system. Thus, in many new and existing homes there is an occurrence of an out of balance roof ridge/soffit ventilation system.
These out-of-balance ventilation systems are subject to several problems, one of which is the infiltration of moisture through the ventilators. An out of balance system favoring the soffit vents will produce a weak ventilation system but little harm will occur from infiltration of moisture through the roof ridge or soffit ventilators into the space below the roof of the building. In an out of balance system favoring the roof ridge ventilators, however, a phenomenon occurs in response to normal winter winds that will infiltrate moisture such as snow through the roof ridge ventilator. This infiltration of moisture phenomenon is described in detail and is solved, for example, in U.S. Pat. No. 4,325,290 which is assigned to the assignee of the present invention and hereby is incorporated by reference.
This type of existing ventilator system restricts infiltration of moisture by providing a high impedance to moisture while presenting a low impedance for air passing through the ventilator. Such ventilators typically are formed from aluminum, rolled sheet zinc or like material with a high profile. Thus, they may be somewhat difficult to handle and install, cannot readily be adjusted to accommodate different roof pitches, and cannot be shingled over which, when combined with its high profile, tends to be unsightly on the roof of a house.
Recent studies also have indicated that a free flow of air within a structure tends to affect infestation of insects, such as cockroaches. Such insects tend to accumulate in enclosed, dark spaces where there is little or no air movement, such as attics, soffits and overhangs on houses and smaller commercial and industrial buildings. Moving air apparently bothers the hair and/or antennae on their bodies causing these insects to seek out an enclosed dark space. Thus, a free flow of air within a structure combined with appropriate filter members utilized with the roof ridge and soffit ventilators, can provide an effective means of pest control.
The roof ridge ventilator of the present invention provides a low profile, unitary ventilator that establishes proper air flow through the attic, restricts insects and the elements from entering through the ventilator, can be adjusted on sight to accommodate a variety of roof pitches and openings and can be shingled over to match the shingles of the remaining portion of the roof.